Fishhook Waterflea

Photo by Igor Grigorovich,

Additional Images

Common Name: Fishhook waterflea
Scientific Name: Cercopagis bengoi
Origin: Eurasia


Fishhook waterfleas are tiny crustaceans less than 1/2″ long with long, sharp, barbed tails. The fishhook waterflea has a slender spine and prominent S-shaped loop on the tail. Fishhook waterfleas collect in gelatinous globs on fishing equipment and lines.


Fishhook waterfleas thrive in deep lakes but can also be found in shallow lakes and rivers.


Fishhook waterfleas are voracious predators of small zooplankton, like Daphnia, an important food for young native fishes. They reproduce rapidly and eggs are capable of lying dormant all winter, resisting drying and freezing. As a result of their sharp spines, smaller fish cannot readily consume them, adding to their explosive populations.

NYS Threat Ranking Assessment Score = Very High, 84.04


No control methods exist. Prevention is key. Since fishing and boating equipment is the most likely means of spread, anglers and water-users must take precautions. Boats and gear should be thoroughly checked, cleaned, and dried before entering new waterways.

Distribution: View Map


This species was found in Lake Champlain in 2018.